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FAQ # 6

Red Light Camera Studies:
Alternatives to Cameras
(Engineering Countermeasures)

Updated 1-8-12

Question:  Engineers who have studied red light running - those who do not stand to gain financially from the use of red light cameras - suggest that cities try alternatives to cameras before installing cameras.  Why is that, and what are the alternatives?

Part (A) of Answer:  One alternative is to lengthen the yellow light, which is known to dramatically reduce the number of cars running the lights.  One study - details below - showed a 69% decrease in violations when a yellow was increased from 4.0 seconds, to 4.5 seconds.  Other studies - details below - gave similar results, and also rated engineering countermeasures such as longer yellows "most effective" in reducing unintentional running while enforcement, including cameras, was considered "less effective."

"Research has consistently shown that drivers do not, in fact, adapt to the length of the yellow." [Determining Vehicle Change Intervals - A Proposed Recommended Practice", ITE, 1985]

"Olson and Rothery reported in 1972 that their research showed that drivers were 'virtually' certain to stop if their required deceleration rate was less than 8 feet per second squared [ 0.25 G ] and virtually certain to continue if the deceleration rate required was in excess of 12 feet per second squared [ 0.38 G ]." [Determining Vehicle Change Intervals - A Proposed Recommended Practice", ITE, 1985]

Part (B) of Answer:  Another alternative is to improve street markings.  2005 research sponsored by the Florida Department of Transportation concluded that improving street markings (plain old paint!) near intersections would reduce red light running by up to 74 percent.  (Section 3.4, p. 69 of the document, or p. 84 of the pdf.)  A large red light camera study sponsored by the San Diego Police Department rated engineering countermeasures such as better markings as "most effective" in reducing unintentional running whereas enforcement, including cameras, was considered "less effective."  (Table 6.3, p. 80 of the document, or p. 97 of the pdf.)

A couple more engineering countermeasures are larger signal lamps (12" dia. instead of 8"), adding backboards to the signals and, where there is no signal light on the "near side" of the intersection, adding one.  highwayrobbery.net suggests that cities should put up large lighted name signs, including for the smaller cross streets.  

Adding these cues becomes even more important when the intersection is missing much of the urban junk - gas stations, crossing overhead utility lines, commercial signage, bus benches - that usually demarks signalized intersections in an urban area. 

Culver at Farwell in Irvine, Site of Jan. 2011 Fatal Crash

There's no denying that a clean spare look, like this intersection in Irvine, is attractive, but if you don't have the urban junk you need to add  other visual cues.

Visual cues are also important where there's too much urban junk competing for drivers' attention, as at the two intersections pictured below.

Impending crash at St. Georges/Stiles, Linden, NJ, site of an ATS camera
(White arrows point to signals, which are yellow.  The driver turning left was found to be at fault.  See discussion on the Industry PR page.)

Reseda Blvd. at the Busway, in the San Fernando Valley, site of a camera operated by the Metro/MTA

Internal documents from the City of San Diego show numerous intersections rejected as camera sites, with the notation, "long yellow - vio(lation) volume not there" - an Industry acknowledgment that at intersections with longer yellows, there will not be enough violations to make the system pay.

If you want to find out if the City studied or applied countermeasures at the intersection where you were ticketed, ask them about it, via a public records request.